Ion Mobility Spectrometry (IMS) is an analytical technique that has been used for military or security purposes, such as for detecting drugs and explosives. IMS is based on separation and identification of ionized molecules according to ion mobility of the ionized molecules under an applied electrical field. In a simplest form, IMS measures how long ions of a sample traverse a given length in a drift tube driven by the applied electric field. During operation, in specified intervals, a batch of the ions are introduced into the drift tube. The applied electric field then drives the ions through the drift tube during which the ions separate based on corresponding ion mobility values. The separated ions then arrive at a detector (e.g., a Faraday plate or mass spectrometer) to be recorded as a profile in order from the fastest to the slowest ions. The recorded profile, or a mobility spectrum, can represent a characteristic signal for a chemical composition in the sample. As such, the chemical composition in the sample can be identified.